Use higher QoS for WheelEvent and DisplayWasRefreshed IPCs since those are high priority. The UIProcess's main thread has high UserInteractive QoS but the IPC thread has a lower QoS by default. We cannot raise the QoS of the IPC thread without regressing some performance benchmarks since not all IPC is high priority.
<rdar://82657744>
Created attachment 442751 [details] Patch
This is causing WKWebView.PrepareForMoveToWindowThenClose API test to fail. I am investigating.
Created attachment 442850 [details] Patch
Created attachment 442867 [details] Patch
Committed r285159 (243795@main): <https://commits.webkit.org/243795@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 442867 [details].